The number of people sickened in a salmonella outbreak at Sheetz Inc. convenience stores around the region increased to more than 60 yesterday, as the state Department of Agriculture tested food samples to determine its source.
Health officials believe the illness came from produce that was already contaminated when it was shipped to Sheetz stores. The victims became ill after eating in a number of stores throughout Pennsylvania and neighboring states, said state Department of Health spokesman Richard McGarvey.
Agriculture officials took samples on Friday and Monday of tomatoes, lettuce, mayonnaise and cheese from several stores linked to the outbreak, and test results are expected today. McGarvey said the health department has found no evidence that contaminated food has reached other restaurants or stores.
Two epidemiologists and a third investigator from the U.S. Centers for Disease Control and Prevention were to arrive in Pennsylvania last night to help search for the outbreak's source and interview its victims.
They will help to interview sick people about what they ate and to analyze that information, CDC spokesman Dave Daigle said. The U.S. Food and Drug Administration also will help to trace the origin of suspect food, he said.
Of particular interest to state and federal investigators are prepackaged supplies of Roma tomatoes and lettuce, which are used by store workers to assemble sandwiches and salads in store delicatessens, because the strain of salmonella causing the outbreak is often linked to produce.
If tests also detect that strain in foodstuffs removed from Sheetz stores, investigators then will try to trace in reverse the path that the items took from farm to deli counter and to determine how they were contaminated, he said. Investigators believe the outbreak began with food consumed since the beginning of the month.
"If we get a [positive test], that's a smoking gun that could make it easier to trace it back," McGarvey said. "But we're testing only the product that was left over in stores. If [the outbreak] was caused by one bad batch from early July that's been all used up, we may not see anything."
Sheetz Inc. Chairman Steve Sheetz, who spent much of yesterday visiting and eating in his Altoona-based company's stores in an effort to maintain confidence among customers and employees, said he believes that tomatoes, not lettuce, are to blame. Although his chain replaced supplies of both tomatoes and lettuce this week, Sheetz noted that past outbreaks caused by the salmonella Javiana strain have been linked to Roma tomatoes.
The company has sanitized stores, changed produce suppliers and removed all Roma tomatoes from its 300 stores in Pennsylvania and five other states. Those tomatoes, which arrive in stores already sliced in vacuum-sealed packages, have been replaced with hothouse tomatoes obtained from other vendors, he said.
"Once we found that Roma tomatoes were associated with some outbreaks, that was enough for us," said Sheetz, who said he didn't know how much it cost to discard and replace those supplies.
"We are in business for the long term and what it costs should not come into consideration when it comes to customer and employee safety," he said. "We'll add it up and move on."
Sheetz said it was too early to gauge if customers have been scared off by the outbreak or reassured by the company's response to it.
"It is up to them to decide if they have confidence in us, no matter what I say," he said. "I do, obviously, feel comfortable eating at Sheetz and I hope they do, too."
Sheetz Inc.'s previous produce supplier, Coronet Foods of Wheeling, W.Va., also said it has stopped buying and processing Roma tomatoes and has quarantined its remaining supply while it conducts its own investigation.
In a statement yesterday, Coronet officials called those actions precautionary measures, saying they had not been officially notified but were aware that the investigation had "narrowed" to Roma tomatoes. They said they have resanitized their tomato processing line, which is separate from other food-handling operations, and have notified growers and suppliers of the outbreak.
Coronet, which supplies fresh-cut items to restaurants and food retailers, said its tomato-processing operation represents only 1 percent of its business and nearly all of its tomatoes were distributed to Sheetz.
Salmonella bacteria live in the intestinal tracts of humans and other animals, including birds. The bacteria are usually transmitted to humans by eating foods contaminated with animal feces.
John Stella, the regional food safety officer with the agriculture department, said produce can become contaminated by an environmental problem at a farm. Infected individuals who harvest, wash, or pack produce could also contaminate food by failing to wash their hands with soap after using the bathroom.
The state Department of Health said at least 50 Pennsylvanians in 12 counties have confirmed cases of salmonellosis, up from 34 on Wednesday. The initial 34 people all reported that they ate food purchased at a Sheetz store. A cluster of them were from Westmoreland County, where 15 people have been treated at Mercy Jeannette Hospital and 20 others have been treated at Westmoreland Regional Hospital, hospital officials said.
Health officials also have reported 14 cases in Maryland and one in West Virginia as well as other probable cases in those states and Virginia and Ohio. Now that the probable source of the outbreak has been identified, however, McGarvey said health officials believe it will ebb.
People infected with salmonella bacteria generally develop diarrhea, nausea, fever and abdominal cramps within 12 to 72 hours. Most recover within seven days without treatment.
No deaths have been reported in the region, although the infection can cause dehydration and pose a serious threat to people with weakened immune systems. It can also cause Reiter's syndrome, a malady that irritates joints and the eyes and can lead to chronic arthritis.
McGarvey acknowledged that symptoms of salmonella infection are similar to those suffered by 660 people who contracted the hepatitis A virus after eating at a Chi-Chi's restaurant last fall in Beaver County. Four people died in that outbreak, in which contaminated green onions from Mexico were implicated.
Because that outbreak was so recent and widespread, Pennsylvanians may be particularly nervous about the threat posed by another food-borne illness, he said. But the two ailments are very different,starting with the relatively short incubation period for salmonellosis that has allowed health officials to track it relatively quickly after noticing an increase in reported cases last Friday.
By contrast, McGarvey said, the incubation period for hepatitis A was two to four weeks, so local victims didn't start getting sick until their memories had started to fade about what and where they'd eaten weeks before. By that time, they had unwittingly had the opportunity to expose others around them to the disease.
Salmonellosis causes an estimated 1.4 million illnesses each year in the United States and around 2,000 each year in Pennsylvania. The Javiana strain sickening people in Pennsylvania is the fifth most common type of salmonella bacteria, accounting for 3.4 percent of all cases reported to the CDC during 2001.
The last U.S. salmonella outbreak of this type occurred in 2002, sickening 141 people from 32 states while they attended the U.S. Transplant Games in Orlando, Fla. Laboratory tests indicated that diced Roma tomatoes being served at the games were contaminated.
Even with yesterday's increase in cases, the outbreak is still far from the largest ever in Pennsylvania. In 1995, roughly 300 Pennsylvanians were sickened in a salmonella outbreak from contaminated bologna, said health department spokeswoman Jessica Seiders.